Instrument panel assemblies



May 22, 1962 R. W. ROSS INSTRUMENT PANEL ASSEMBLIES Filed May 4. 1959 4Sheets-Sheet 1 Fig. l

y 1962 R. w. R088 3,035,446

INSTRUMENT PANEL ASSEMBLIES Filed May 4, 1959 4 Sheets-Sheet 2 F g. J: II I I I I I I MN-NAM IIIIIIIII.

I, II

I QFI ,,,,zma

May 22, 1962 R. W. ROSS INSTRUMENT PANEL ASSEMBLIES Filed May 4, 1959one 4 Sheets-Sheet 3 May 22, 1962 R. w. R058 INSTRUMENT PANEL ASSEMBLIESFiled May 4, 1959 4 Sheets-Sheet 4 4a 60 q I, 20c A:.: s2 l9f- I99 I96 g-20. l8 p, 1 B 20 l6f 6g l8f 3,035,446 INSTRUMENT PANEL ASSEMBLIESRaymond W. Ross, Cheltenham, Pa., assignor to Leeds and NorthrupCompany, Philadelphia, Pa, a corporation of Pennsylvania Filed May 4,1959, Ser. No. 810,906 11 Claims. (Cl. 73-432) This invention relates tomeasuring instrument panel structures and has for an object theprovision of a panel assembly for receiving flush-mounted instrumentsand accessories of widely differing dimensions and which has structuralprovisions avoiding the need to cut openings in solid panel structures,thereby to eliminate waste of material while at the same time providinga structure which is strong, rigid, and unusually attractive inappearance and one which may at any time be enlarged without destroyingits attractive appearance.

For many years measuring and controlling instruments have been supportedupon solid panels having cut-outs to receive the various instruments.Such panels have been made of a variety of materials including slate andsteel, which materials, in general, have required relatively expensiveoperations to provide the necessary cutouts, and much material has beenwasted.

In carrying out the present invention, there is provided a panelassembly for instruments for measuring and controlling magnitudes ofconditions in which the width of the openings for the instrumentscorrespond with the sum of the widths of a selected number of panelmembers and in which the heights of said openings are determined by thelengths of the panel sections above and below the location of aparticular opening. The panel members are of differing widths and are sodisposed in the panel assembly as to provide in that assembly openingsof diflerent widths, each selected to accommodate an instrument of thecorresponding width. In this manner, there are avoided the operationsincident to cutting from a solid panel openings to receive instrumentsof variable dimension. Not only is there achieved a saving in labor andmaterials, but there is also achieved a construction highly versatile inits ability to accommodate with a minimum of operations instruments ofwidely differing dimensions.

Further in accordance with the present invention, the several panelmembers are formed of extruded material, such as aluminum. The severalpanel members, including those of variable width, have on their frontfaces vertically extending flutes and ribs disposed in symmetricalarray. By means of mechanical interlocking structure, such as tonguesand grooves, the panel members interconnect one with the other tomaintain across a plurality of panel members the symmetrical dispositionof the flutes and ribs. In this manner, there is provided a panelassembly uniform in appearance notwithstanding the presence ofindividual panel members of variable width. The extruded panel membersrespectively include rearwardly extendingribs adjacent edge portionsthereof to provide the requisite rigidity for each panel member. Becauseof the rearwardly extending ribs, the panel members may be of relativelythin cross-section. Each extruded panel member additionally includes apair of spaced parallel ribs having a series of opposed -serrations forreceiving therebetween the threads of fastening bolts or screws. Thus,cap screws may be located as desired lengthwise of the plurality ofpanel members to secure them to additional supporting structure andbracing members.

Further in accordance with the invention, the extruded end-panel membersinclude not only the serrated screwreceiving ribs, but also largerrearwardly extending ribs providing rigid column supports for the paneltogether with threaded elements adjustable relative to the columnmembers for fastening thereto additional supporting structure for thepanel.

It is also an object of the invention to provide a lowcost, attractive,and durable means for applying to a panel structure graphicrepresentations of a process.

For further objects and advantages of the invention, and for a moredetailed discussion of the manner in which it may be utilized in panelassemblies, references is to be had to the following description takenin conjunction with the accompanying drawings, in which:

FIG. 1 is an isometric view of a panel assembly embodying the invention;

FIG. 2 is an enlarged sectional view taken on the line 2--2 of FIG. 1;

FIG. 3 is an enlarged sectional view taken on the line 3--3 of FIG. 1;

FIG. 3A is an end view of a modification illustrating a combined trimstrip and channel cross-brace;

FIG. 4 is an enlarged fractional View of a portion of the panel assemblyof FIG. 1 and to which there have been added panel-marking members;

FIG. 5 is a sectional view of a modified form of rib and fluteconfiguration with marking members;

FIG. 6 is an isometric view of a panel-marking member;

FIG. 6A is an end view of a modified form of marking strip;

FIG. 7 is a rear view of a portion of the panel assembly of FIG. 1; and

FIGS. 8, 9 and 10 are enlarged cross-sectional views which together havebeen taken along the section line 8, 9 and 10 of FIG. 1.

Referring now to FIG. 1, there has been illustrated a panel assemblyembodying the invention and comprising two panel sections 10a and 10b.In panel section lllb there are illustrated openings or windows toreceive instruments for the measurement and/or control of variableconditions. Such instruments may widely differ in width and height. Forexample, the recording and measuring instrument 31 of panel 10a requiresan opening,

such as opening 11, much larger than the opening 12 of a size toaccommodate a control-instrument 32. The instrument 33 is of a stilldifferent size and requires an opening 13 diflering from openings 11 and12.

In accordance with the present invention, it is to be noted that theopenings 11, 12 and 13 have been provided by the simple expedient ofcutting panel members to predetermined lengths. A number of the panelmembers 142ti are of differing widths and in the regions of the openingsthey have been assembled so that the sum of the widths of a selectednumber of panels will be equal to the desired width dimension for therespective openings. The end panel members 14 and 20 of sections 10a and10b, FIGS. 1,8 and 10, are continuous from top to bottom. The panelmember 15, FIGS. 1

and 10, comprises a lower portion 1511, FIG. 1, having a length suchthat the top thereof terminates at the bottom of the opening 11. Theupper portion 15b has a length such that its lower end terminates at theupper edge of opening 11. Similarly, panel members 1618, FIGS. 1, 8-10,are made up of lower portions 16a--18a, FIG. 1, intermediate portions16b18b, 16c18c and upper portions 16d18d. This is true with respect topanel members 17a-17b. The panel member 19, FIGS. 1 and 8, has a lowerportion 1911, FIG. 1, and an upper portion 1917. It is to be understoodthat the several panel members are all extruded, as from aluminum, andall are delivered with predetermined lengths. Thus, to provide theindividual portions of a panel member, such for example, as panel member17, it is only necessary to cut from a single length of stock theseveral portions 17a, 17b, 17c and 17d. Thus, there is avoided all lossof stock material, notwithstanding the provision of the three windowsillustrated in the embodiment of FIG. 1.

As shown in FIGS. 1, 8, 9 and 10, the panel members 15 and 19 have equalwidths of 3%". The panel members 16 and 18 have equal widths of 2%",while the panel member 17 has a width of Thus with the tongues set inthe cooperating grooves, the opening 11 has a width of 16 /3, adequateto accommodate the width of instrument 31. Opening 12 has a width of thesame as the width of opening 13. Instrument 33 requires a window 13 ofgreater height than window 12 and as will be seen, this is provided byreducing the lengths of the lower portions 16a, 17a and 18a byappropriate amounts. In the embodiment of the invention illustrated inFIG. 1, the openings 11, 12 and 13 had heights respectively of 18%;", 64 and 10%;".

The panel assembly 10 has a top trim strip 21 formed by an angle-member,the front portion of which, FIG. 2, extends along the front of the paneland the top portion of which covers the top of the panel. The trim stripor angle-member 21 is secured in place as by a plurality of bolts andnuts 22 which extend through openings in the top portion of angle-member21 and through mating openings in a channel-shaped brace or cross-member23 having inturned ends 2311 and 23b. The upper portion 18d of panelmember 18 is secured to the panel member 23 by a machine screw 24. Themanner in which the screws 24 secure panel portions in place will bereadily understood in connection with the description of the sectionalviews of FIGS. 8 to 10.

A trim strip 25 formed by an angle-member is provided at the lower endof the panel assembly 10 and is fastened to a channel member 26, FIG. 3,also having inturned ends. These inturned ends are arranged to nestwithin grooves in a nut 27 which receives a cap screw 28 to securetogether an angularly-shaped corner plate 29 and a 90 angle bracket 30through which may extend a screw 34 to anchor the panel assembly to thefloor. Braces 35 are secured to the back of the panel and to the floor,one such brace appearing in FIG. 1 and two of them appearing in FIG. 7.

Referring now to FIG. 3A, it will be observed that the channel 26 andthe trim strip 25 of FIG. 3 have been combined into a single extrudedstructure including the channel 26a and the forward trim strip 25a. Thestructure of FIG. 3A may be utilized for the top trim panel and channelstructure as shown in FIG. 2. By utilizing the structure of FIG. 3A, theupper and lower channels 23 and 52 of FIG. 7 may extend the full widthof the panel section 10b, and if desired, it may extend across all panelsections, that is to say, across both panel sections 10a and 10b ofFIG. 1. Thus, the extruded trim and channel section of FIG. 3A may insome instances be preferred in that it will simplify the assembly of theseveral parts and will provide added rigidity.

In order to provide a symmetrical and pleasing pattern for the front ofthe panel assembly, the panel members have vertically extending flutesand ribs best shown in FIG. 4 and in FIGS. 8-10. Thus as viewed in FIG.4, the flutes and ribs render indistinguishable the meeting lines of theseveral panel members. The flutes and ribs have additional functions.Thus, the recording and indicating instrument 31 may have in associationtherewith a graphic representation of the apparatus from whichmeasurements are being made and recorded by the instrument 31. As shownin FIG. 4, the instrument 31 is located in associaton with arepresentation of a vessel 36 from which there extends a flow line 37which on the panel as a whole leads to other associated apparatus (notshown). An additional flow line 38 extends from the representation ofvessel 36 to other associated apparatus not shown in FIG. 4.

For an electrical measuring circuit or a circuit for controlling themagnitude of the condition under measurement, there appearsrepresentation of an electrical line 39 extending from the instrumentitself to another portion of the panel assembly. While representationson panels of instruments, lines and circuits have heretofore beenutilized, and are commonly referred to as Graphic Panels, the flutes andribs of the panel assembly of the present invention have been utilizedfor the achievement of great flexibility in the kind of flow diagramswhich may be utilized. Thus, by providing channel-shaped marking members40, such as shown in FIG. 6, made of a plastic material anddistinctively colored, graphic representations may be added to, changed,and otherwise utilized to provide the maximum information on the face ofthe panel as to the nature and character of the measurements andcontrolling operations performed by the instruments on the panelassembly.

While synthetic resins and plastic materials of the type which may bereadily extruded and available in distinctive colors are to bepreferred, it is to be understood that channel members of othermaterials and of shape similar to the one illustrated in FIG. 6 may beutilized with or without the inturned ends 40a and 4012. These inturnedends, as illustrated in FIG. 5, are preferably utilized when the fluteshave dovetail shapes, as shown in FIG. 5. Two adjacent channel markingelements 41 and 42 have their side portions pressed into a flute 43 of apanel member 44 with their opposite edge portions pressed into flutes 45and 46. It is in this manner, as shown in FIG. 4, that graphicrepresentations may be placed on a panel with the measuring instruments.By utilizing channel markers in spaced relation spanning alternate ribsas illustrated for the line 39, it will be seen that a wide variety ofcombinations of colors in solid and broken-line array may be utilizedfor symbolic representations of complicated systems. Since the channelmarkers are made of a synthetic, resilient plastic, such as polyvinylchloride or polyethylene, they are readily cut to length and shape byordinary shears, scissors or a sharp knife. As shown in FIG. 6A, thechannel markers may embrace more than a single rib, and such channelmarkers may be die-cut into more complicated designs representative ofvalves and the like. As shown in FIG. 6A, there extend from the frontsurface 70 three legs 70a, 70b and 700. Legs 70a and 70c correspond withthose illustrated in FIG. 6. The intermediate leg 70b is of doublethickness and has a V- shaped cut-out (formed during the extrudingprocess) to make easier the insertion of the central leg in one of theflutes and with retainment of the advantages of the locking-beads 7012provided on opposite corners of the central leg 70b.

Referring now to FIG. 7, there appears a rear view of the panel section10b and a portion of the panel section 10a. Across the top of panelsection 10b there extends the channel 23. This channel, like channel 50of FIGS. 8 and 10, terminates adjacent columnar portions of end panelmembers 14 and 20. It will be observed, FIGS. 8-10, that the severalpanel members are mechanically interlocked. Thus, the left-hand edge ofpanel member 20 has a groove to receive a projecting tongue of panelmember 19. Similarly, the left-hand edge of panel member 19 has a grooveto receive a tongue of panel member 18. The opposite edge of panelmember 18, FIG. 9, has a groove to receive a tongue of the wider centnalpanel member 17. The left-hand edge of this panel member 17 also has atongue which fits into a groove of panel member 16. Panel member 16 isidentical in construction with panel member 13. Panel member 15corresponds with panel member 19 and has a tongue at its lefthand edgeportion, FIG. 10, fitting into a groove of panel member -14. This panelmember 14 is of the same construction as panel member 20.

Each panel member has a plurality of rearward extensions. Thus, at theright-hand edge of panel member 19 there is provided a rib or extension1% and, at the lefthand portion, two closely spaced ribs 19f and 19g.These ribs have serrations extending lengthwise of the ribs and of shapegenerally complementary to the threads on fastening screws 48 extendingthrough the web of channel member 50. The wider central panel member 17has its parallel serrated ribs 17 f and 17g intermediate its ends and inaddition, has adjacent the edges reinforcing ribs 17m and 1711. Thus itwill be seen that each panel member or a portion thereof is providedwith a plurality of stiffening and supporting ribs respectively tightlyclamped to the channel 50 and similarly clamped against additionalchannel members 23, 51 and 52, two of which as shown in FIG. 7, extendacross the upper ends of the panel members adjacent the openings 11 and13. The several panel members are characterized by the provision of aplurality of such stiffening ribs, at least one of which is locatedadjacent the respective edge-portions of such panel members. Inaddition, stiffening ribs including provisions to receive cap screws areprovided adjacent the tongue and groove interlocking assembly ofadjacent panels. Thus while the cap screw 48 is effective through thetongue and groove connection 18p in cooperation with the stiffening rib18e, for the panel 17 the serrated ribs 18,-f and 18g and the serratedribs 16f and 16g are effective through the tongue and groove connections16p and 18p to clamp the stiffening ribs 17m and 17m against channelmember 50.

The channel members 23 and 52 are secured to the end panel members 14and 20 by means of corner plates 29. The intermediate channel members 50and 51 are secured to the end panel members 14 and 20 by means ofT-shaped plates 54. There will be included, as required, additionalpanel portion supporting and reinforcing members for the panelstructure, such for example, as member 55 which, it will be observed, islocated intermediate the openings 12 and 13 and has a lengthsufliciently greater than these openings so that it will be fastened tosupported panel portions 15a and 18a and, in turn, support the panelportions 16b, 17b and 18b (FIG. 1). Such intermediate supporting membersmay be located in any selected position, either in the position shown inFIG. 7 or nearer to one or the other of openings 12 and 13.

The instruments 31--33 of 'FIG. 1 are mounted on the panel assembly asfollows. Each instrument is provided with a rim or flange of greaterwidth and height than the associated opening. Thus an instrument can bepushed through the opening from the front of the panel toward the rearthereof. For heavy instruments the associated flanges may have extendingrearwardly therefrom studs which may be received by openings 57, FIG. 7,provided in panel members 14 and 20. Inasmuch as the channel member 50has an upper edge coinciding with the lower edge of opening 11, it willbe seen that the weight of the instrument for that opening will be takenby the channel member. Thus the studs which will protrude throughopenings 57 serve to hold the instrument snug against the front of thepanel and not to provide the whole support thereof from the panelmembers. The panel members can support the instruments, however.

Thus, an instrument mounted in opening 12 may have studs extendingthrough openings 58 to which there will, of course, be applied washersand nuts.

An additional variation has been illustrated for the opening 13. Thoughthe instrument does not appear in FIG. 7, there have been illustratedclamping plates 59, one of which is received on studs carried by theinstrument and extending through the opening 13 adjacent the boundariesthereof. By tightening fastening nuts, the clamping plates 59 arepressed against the adjacent panel members to clamp the instrument infixed position.

Referring now to FIGS. 8, 9 and 10, it is to be noted that while thesection line =8, 9, 11 has been taken across the panel section 10a, andwith the instrument 31 omitted therefrom, the reference characters forthe parts are the same as for the panel section 10b, the parts beingidentical in the two panels. Referring to the right-hand panel section20, FIG. 8, it will be observed that there is included a channel section200 arranged to receive a threaded member 60 which by means of a capscrew 61 secures the T-shaped member 54 thereto. For ease in threadingthe screw 61 into member 60, a compression spring 62 holds the threadedmember 60 against the inturned ends of the panel section 290 of panelmember 20. The righthand end of panel member 20 has a rearwardlyextending side to provide additional strength to the panel assembly andto conceal the T-shaped member 54 and the heads of the cap screws. Theintermediate channel member 50 has its web portion secured to the ribs20 and 20g of panel member 20 as by a cap screw. The channel member 50is also secured to the T-shaped member 54 as by cap screw 63 and by acooperative nut and spring assembly like that described for cap screw61.

As already described, the panel section 19 is clamped against channelmember 59 as is each of the panel members 15-19. The left-hand panelmember 14, FIG. 10, is identical with panel member 20, but it will benoted that it has been turned end-for-end. The left-hand T- shapedmember 54 of FIG. 7 appears in FIG. 10 and has associated therewith capscrews 61a and 63a which in conjunction with associated fastening meanslike that of FIG. 8 secure together panel member 14 and channel member5%. The left-hand panel member 14 of panel section 111a is bolted topanel member 26 of section 10b (FIGS. 1 and 10) by a plurality of bolts,one of which, the bolt 65, is shown in FIG. 10.

It will be observed that a spacer 66 separates the two panel members 14and 2t} and that there is interposed between them a rectangular-shapedmember 67 which provides at the front of the panel a back surface forthe space between them in duplication of the back wall of a flute. Inthis connection, it will be noted that the groove 20: FIG. 8, is formedby a narrow, deeper groove adjacent a shallower and wider groove, thelatter providing space for the spacer member 67, the deeper groove beingprovided to receive the tongue of other of the panel members whendesired.

The panel assembly as a whole is rigid, mechanically interlocked, withas many weight-carrying columns and cross-channel members as needed tocarry loads of any magnitude which may be imposed by instruments ofwidely differing character. The panel assembly is characterized by themultiplicity of panel members, all of ex truded material, such asaluminum, and which by reason of the provisions described above providegreat fiexibility in assembly with the simplest of mechanical operationsto provide most openings at almost any desired locations, together withan attractive appearance which may include flow charts and othersymbolic representations of processes or systems for which the panelassembly is to be used.

What is claimed is:

1. A panel assembly of substantial width and height for instrumentscomprising a plurality of extruded panel members, each of said panelmembers along opposite edges having means for mechanically interlockingthem one with the other, a substantial number of said panel members.

being of substantially different widths to provide differing distancesfrom an edge of one panel member to an opposite edge of another panelmember, the sum of the widths of selected panel members being at leastequal to the width of an instrument to be carried by them to provide ahorizontal dimension for a panel opening to receive such instrument,said panel members terminating lengthwise along horizontal linescorresponding with the height of the instrument at the desired locationin the panel assembly whereby instruments may be mounted at selectedpositions determined by the length of the panel members above and belowthe instrument location, and cross-members extending across the panelmembers in line with an opening and secured to panel members adjacentsaid opening.

2. The panel assembly of claim 1 in which each said panel member hasadjacent at least one edge thereof a rearwardly extending rib forstrengthening said panel along the edge portion thereof, saidstrengthened edge through said mechanical interlocking means likewiseproviding strength for the edge of an adjacent panel member.

3. The panel assembly of claim 2 in which a plurality of said panelmembers are provided with spaced rearwardly extending ribs havingserrations on opposing surfaces adapted to receive threaded screws atany selected position along the lengths thereof, and bracing membersoverlapping a plurality of said panels and secured thereto with screwsextending into said serrated ribs for stiffening said panels to holdthem in position to maintain said symmetrical pattern, said rib adjacentan edge thereof having the same rearward dimension as said spaced ribsfor contact with the said bracing member.

4. The panel assembly of claim 1 in which said mechanical engaging meansfor said panel comprises tongues and grooves at adjacent edges of saidpanels for interlocking engagement one with the other.

5. A panel assembly of substantial width for measuring instrumentscomprising a plurality of panel members having at their respectivelongitudinal edges tongues and grooves disposed for interlockingengagement to form tongue and groove joints, each said panel memberhaving rearwardly extending stiffening ribs adjacent each said joint, across-member against which said ribs are disposed to bear, said ribs ofsaid several panel members having provisions to receive threadedfastening members adjacent each said tongue and groove joint forstiffening said panels by the clamping action of the ribs on oppositesides of each said tongue and groove joint against said cross-member.

6. The panel assembly of claim 5 in which a plurality of panel membersintermediate the end panel members are made up of a plurality ofportions of differing lengths to provide a plurality of openings throughwhich instruments may extend, there being adjacent a plurality of saidopenings, channel members for additional stiffening of said panels andfor carrying the weight of the instruments.

7. A panel assembly of substantial width for measuring instruments,comprising a plurality of panel members having on their front facesvertically extending flutes and ribs in symmetrical array, each of saidpanel members .along their longitudinal edges having means formechanically interlocking them one with the other and in a spacedrelation which maintains the symmetrical pattern from one panel toanother, each said panel member having adjacent at least one edgethereof a rearwardly extending rib for strengthening said panel alongthe edge portion thereof, said strengthened edge through said mechanicalinterlocking means likewise providing strength for the edge of anadjacent panel member, said panel members having Widths to provide in aselected location of the assembled panel members an opening having adimension extending from an edge of one selected panel member to anopposite edge of another selected panel member equal to the widthrequired for a measuring instrument, said panel members in the region ofsaid opening being of decreased length to provide a panel opening equalto the height of said instrument, and cross-members overlapping andsecured to a plurality of said panel members.

8. The panel assembly of claim 7 in which a plurality of said panelmembers are provided with spaced rearwardly extending ribs havingserrations on opposing surfaces adapted to receive threaded screws atany selected position along the lengths thereof, and bracing membersoverlapping a plurality of said panels and secured thereto with screwsextending into said serrated ribs for stiffening said panels to holdthem in position to maintain said symmetrical pattern, said rib adjacentan edge thereof having the same rearward dimension as said spaced ribsfor contact with said bracing member.

9. A panel assembly of substantial width for measuring instruments,comprising a plurality of panel members having on their front facesvertically extending flutes and ribs in symmetrical array, each of saidpanel members along their longitudinal edges having means formechanically interlocking them one with the other and in a spacedrelation which maintains the symmetrical pattern from one panel toanother, a plurality of said panel members including channel-shapedsections to provide columnar supports, each of said channel portionshaving inturned ends for supporting threaded members slidable lengthwisethereof, said panel members having widths to provide in a selectedlocation of the assembled panel members an opening having a dimensionextending from an edge of one selected panel member to an opposite edgeof another selected panel member equal to the width required for ameasuring instrument, said panel members in the region of said openingbeing of decreased length to provide a panel opening equal to the heightof said instrument, and cross-members overlapping and secured to aplurality of said panel members.

10. A panel assembly of substantial width for measuring instruments,comprising a plurality of panel members having on their front facesvertically extending flutes and ribs in symmetrical array, each of saidpanel members along their longitudinal edges having means formechanically interlocking them one with the other and in a spacedrelation which maintains the symmetrical pattern from one panel toanother, said panel members having widths to provide in a selectedlocation of the assembled panel members an opening having a dimensionextending from an edge of one selected panel member to an opposite edgeof another selected panel member equal to the width required for ameasuring instrument, said panel members in the region of said openingbeing of decreased length to provide a panel opening equal to the heightof said instrument, cross-members overlapping and secured to a pluralityof said panel members, and plastic strips generally of U-shape andcomplementary to the shape of said ribs, the thickness of the legs ofeach U-shaped strip being less than that of the grooves between adjacentribs, whereby a pair of said legs can be pressed into a groove toprovide substantially continuous coverage of selected areas of saidribs.

11. An instrument panel comprising panel structure having throughout itsfront face a plurality of vertical ribs and grooves, a plastic stripgenerally of U-shape and complementary to the shape of the ribs, thethickness of the legs of said U-shaped strip not exceeding half thewidth of the grooves between adjacent ribs, whereby said legs can bepressed into said ribs frictionally to engage the same to hold saidstrips in place and to form a continuous line of said plastic stripextending laterally across said ribs and grooves, said plastic striphaving a width overlapping a plurality of said ribs, said stripincluding a plurality of U-shaped sections, each complementary to theshape of said ribs, the thickness of the legs at the edges of said stripbeing less than that of the groove between adjacent ribs and thethickness of the intermediate legs corresponding with the width of saidgroove, each intermediate leg having a notched end to impart flexibilityto the end portion thereof, each said intermediate leg including alongopposite edges beads to engage said ribs to hold said plastic strip inplace.

References Cited in the file of this patent UNITED STATES PATENTS2,062,094 Kip Nov. 24, 1936 10 Bloedow June 2-9, 1954 Dreyfuss Sept. 21,1954 Aorarnson Oct. 16, 1956 Baldanza Mar. 31, 1959 OTHER REFERENCESProcess Control by Graphic Panel by David M. Boyd, 11. Instruments,November, 1944, vol. 22, pages 1054 to Rowley et a1 Apt 27, 1937 101056- (Ph py in ivi i n

